Earth strata differentiating device



C'R OSg REFERENCE SEARCH PM 1967 J. w. HEIMASTER EARTH STRATA DIFFERENTIATING DEVICE Filed July 27. 1965 2 mam INVENTOR. JOHN W. HEIMASTER wy 4401/ ATTORNEY United States Patent 3,333,893 EARTH STRATA DIFFERENTIATING DEVICE John W. Heimaster, Charleston, W. Va., assignor to Union Carbide Corporation, a corporation of New York Filed July 27, 1965, Ser. No. 475,108 6 Claims. (Cl. 299-1) This invention relates to apparatus for distinguishing between earth strata cut by mining and tunneling machines for the purpose of controlling the direction of travel of such machines. More particularly, this invention relates to a continuously responsive earth strata differentiating device operatively dependent upon the difference in light reflecting ability of earth strata and its application to mining and tunneling machines, particularly remotely controlled continuous mining machines.

A critical problem in the use of mining and tunneling machines, such as, for example, remotely controlled bore mining machines, relates to the necessity to distinguish between earth strata so as to guide the machine within a particular stratum and avoid contact of the cutting means with adjacent strata, which contact can result in serious damage to the machine. In United States Patents 2,752,591 and 3,150,519 there are disclosed devices for continuously distinguishing between earth strata being cut by a continuous mining machine, such as that shown in United States Patent 2,826,402, by determining the relative hardness of the strata. By such means a horizontal boring machine operating, for example, in the mining of coal is maintained within the seam of coal and out of adjacent strata of rock or clay. Operation of these prior art devices is dependant upon the relative force applied to a strata cutting tooth in cutting in situ earth materials of different hardness causing relative mechanical movement within the device. Such movement causes wear and loss of proper adjustment and requires flexible seals to exclude dirt and moisture. Moreover, Wear of the strata cutting tooth detrimentally affects the sensitivity of the device.

It is an object of this invention to provide an earth strata differentiating device which is more sensitive and eflicient than those known to the prior art. Another object of this invention is to provide an earth strata differentiating device which is of simple construction and free of moving parts and flexible seals. Yet another object of this invention is to provide an earth strata differentiating device which is low in cost, easy to service and maintain, and adaptable to use with a variety of existing mining and tunneling machines. A still further object of this invention is to provide an earth strata dilferentiating device of relatively constant sensitivity. These and other objects will readily become apparent to those skilled in the art in light of the teachings herein set forth.

In accordance with this invention, such objects are accomplished by utilizing a principle for differentiating between earth strata which is new to the mining art, that is, the difference in color or relative light reflecting ability of such strata. Broadly, apparatus embodying this principle for use in combination with mining and tunneling machines comprises illuminating means, means responsive to changes in reflected light intensity for converting such changes to electrical signals, means for transmitting the electrical signals to an operator control station, and indicating means adapted to respond to the electrical signals.

In operation, the earth strata differentiating device of this invention effects continuous measurement of the light reflecting ability of the earth material being cut and immediate report of the information to an operator control station, so that knowledge of when the machine is 3,333,893 Patented Aug. 1, 1967 cutting into a stratum adjacent that being mined is received by the operator and utilized to control the mining machine. The invention is particularly useful with remotely controlled continuous mining machines in which the operator is at a remote station, far distant from the cutting face. However, it is broadly applicable to continuous mining machines generally, since sight of the cutting face is ordinarily obscured from the operator. Thus, all continuous mining machines, regardless of the type of cutting mean-s employed, require for safety that the operator be stationed ten to twenty feet behind the point where the cutting action is occurring and a shield of some sort is almost invariably imposed between the operator and the cutting action so that the operator is able to see the freshly cut surface only at a position which is several feet behind the cutting face at any instant. Under such circumstances, the machine can be, and often is, in contact with abrasive or otherwise undesirable strata for several minutes before the operator is aware of the situation. This problem may be remedied in large measure by use of the device of this invention, the illuminating source and means responsive to changes in reflected light intensity being positioned near the cutting elements of the machine to give an indication to the operator that the machine is cutting into an undesirable stratum before he could otherwise become aware of it.

As specifically illustrated herein, the present invention provides the combination with a continuous mining machine having a rotary cutting head equipped with main cutting teeth and provided with a radial arm, of a forwardly extending housing carried on the outer reach of the arm, an auxiliary strata cutting tooth rigidly secured near the forward end of the housing and extending radially of the cutting head beyond the housing for cutting the perimeter of the hole being generated by the main strata cutting teeth of the continuous mining machine, a recess in the housing adjacent the auxiliary strata cutting tooth, a photoelectric cell mounted in the recess for scanning the perimeter of the hole as it is cut by the auxiliary strata cutting tooth, a lamp mounted in the recess for illuminating a point on the perimeter of the hole as it is scanned by the photoelectric cell, an oscilloscope having a rotary trace the rotation of which is synchronized with the rotation of the rotary cutting head, and electrical circuitry connecting the photoelectric cell with the oscilloscope.

In operation, as the rotary cutting head of the mining machine advances, the auxiliary cutting tooth continuously extends to a slight degree the scope of the cut so that the auxiliary cutting tooth would cut into a stratum contiguous to that being mined slightly in advance of the main cutting teeth. Light rays from the lamp continuously impinge upon the freshly cut surface and are reflected from such surface to the photoelectric cell. The output of the photoelectric cell is thus continuously responsive to the light reflecting ability of the freshly cut surface and, in turn, the radius of the rotary trace on the oscilloscope is continuously responsive to the output of the photoelectric cell. Accordingly, when the mining machine is about to enter into a stratum other than that being mined, the auxiliary cutting tooth will first contact such stratum, the different light reflecting ability of this stratum will result in a change in reflected light intensity which, in turn, will result in a change in the output from the photoelectric cell and in consequence an indication on the oscilloscope at the operator control station the instant the adjacent stratum is cut by the auxiliary strata cutting tooth. The course of the mining machine may then be correspondingly corrected and the machine thereby maintained at all times substantially within the stratum being mined.

In the accompanying drawings:

FIG. 1 is a front elevational view of a rotary cutting head provided with the earth strata differentiating device of this invention;

FIG. 2 is a side elevational view of the rotary cutting head of FIG. 1;

FlG. 3 is an enlarged cross-sectional view taken on the line 3-3 of FIG. 1; and

FIG. 4 is a wiring diagram of the earth strata differentiating device and its associated circuitry at a remote station.

As shown in FIG. 1 and 2, auxiliary strata cutting tooth it is rigidly mounted near the forward end of housing 12, which is carried on the outer reach of radial arm A on the rotary head H of a continuous mining machine M. Cartridge lid is mounted in housing 12 and positioned adjacent auxiliary strata cutting tooth lltl. As rotary head H rotates and mining machine M advances in the directions indicated by the arrows, auxiliary strata cutting tooth 1t} continuously enlarges the hole generated by main strata cutting tooth 14 in stratum X. In the drawings, mining machine M is shown in such position that auxiliary strata cutting tooth iii has just exposed a small segment of stratum Y which lies adjacent to stratum X which is being mined.

As shown in FIG. 3, cartridge 16, which is mounted in housing 12 in proximity to auxiliary strata cutting tooth Iii, contains lamp 113 and photoelectric cell 2%, both of which are mounted flush with the surface of housing 12. Electrical leads 22 and 24 are connected to lamp 18 and run through passageway 26 in cartridge 16 and passageway 23 in housing 12 into arm A, from which they extend through suitable slip ring connectors, or the like, to a remote control station. Similarly, electrical leads 3% and 32. extend from photoelectric cell Zti via passageway in cartridge 16 and passageway 28 in housing 12 into arm A and thence to the remote control station. Light rays R from lamp it; impinge upon the freshly cut surface of stratum Y and are reflected by such surface to photoelectric cell 29. The intensity of the refiected light is proportional to the color or light reflecting ability of the freshly cut surface.

As shown in FIG. 4, electrical leads 3i) and 32 connect photoelectric cell 2% to bridge circuit 36 composed of resistors 38, 4d and located at the remote control station. Electrical leads 22 and 24 serve to supply power from battery 44 to bridge circuit 36 and to lamp 18. An oscilloscope as, such as that described in United States Patent 2,620,386, is connected by wires 43 and Stl to bridge circuit 36 to indicate the voltage developed across the bridge as such voltage varies with the output of photoelectric cell 26!. Thus, the relative amplitude of the trace on the oscilloscope screen provides a direct and continuous indication of the light reflecting ability of the particular earth stratum being cut by the auxiliary strata cutting tooth at any instant.

As will be evident to those skilled in the art from the foregoing description, the earth strata differentiating device of this invention is uniquely suited to application to remotely controlled continuous mining machines having rotary cutting heads, but the invention may be advantageously utilized in combination with any tunneling or mining machine to indicate to an operator when the machine has entered an undesirable stratum. In the preferred embodiment of the invention described in detail herein, the earth strata differentiating device is adapted for use with a remotely controlled bore mining machine having a rotary cutting head by providing an auxiliary cutting tooth, so that an indication that the machine is about to cut into an undesirable stratum adjacent that being mined is received before the main cutting teeth have cut into such stratum, and the lamp is mounted on the rotary cutting head in proximity to the auxiliary cutting tooth so that the light rays will traverse the surface as it is cut, by the auxiliary cutting tooth and give a warning of approach to an undesirable adjacent stratum regardless of the position of such stratum with reference to the stratum being mined. It is apparent, however, that the auxiliary cutting tooth may be eliminated and the lamp positioned in proximity to the main cutting teeth, although this will, of course, mean that no indication that the machine is about to enter an undesirable stratum will be received until the main cutting teeth have actually cut into such stratum. It is also clear that While it is preferred to mount the lamp and photoelectric cell on the rotary cutting head of the mining machine so that the light rays traverse or scan the freshly cut surface, they may instead be mounted elsewhere on the machine where they will not rotate, although necessarily in proximity to the cutting head. With such an arrangement it may, in some instances, be desirable to utilize a plurality of lamp-photoelectric cell combinations facing in different directions, for example, one lamp directed vertically upward and another directed downward with a separate oscilloscope for each located at the operator control station. Moreover, in instances where a deposit being mined has boundaries in the horizontal plane, unlike coal deposits, the lamp and photoelectric cell may be suitably positioned to indicate when the machine is moving out of the stratum in a horizontal direction into a laterally adjacent stratum.

In light of the disclosure herein, the general applicability of the principle for differentiating between earth strata of the present invention to all types of continuous mining machines, whether engaged in the mining of coal or other minerals, will be apparent to those skilled in the mining art. Moreover, it will also be evident that the device of this invention provides unusual simplicity of construction, low initial cost, and complete freedom from moving parts subject to wear and concomitant error and thereby overcomes many of the disadvantages of prior art devices intended to serve the same general purpose.

The invention has been shown and described in a single preferred form and by Way of example and obviously variations and modifications can be made therein without departing from the spirit and scope thereof, so that the invention is not to be limited except insofar as such limitations are specified in the following claims.

What is claimed is:

ll. An earth strata differentiating device for mining and tunneling machines having earth strata cutting means mounted thereon comprising, in combination, illuminating means mounted in proximity to said earth strata cutting means for lighting a point on the surface cut by said earth strata cutting means, means responsive to changes in the intensity of light reflected from said point mounted adjacent said illuminating means for converting said changes to electrical signals, means for transmitting said electrical signals to an operator control station, and indicating means located at said operator control station adapted to respond to said electrical signals, whereby the light reflecting ability of said surface is continuously indicated at said operator control station.

2. An earth strata differentiating device for a remotely controlled bore mining machine having a rotary cutting head with earth strata cutting means mounted thereon comprising, in combination, illuminating means mounted in proximity to said rotary cutting head for lighting a point on the surface cut by said earth strata cutting means, means responsive to changes in the intensity of light reflected from said point mounted adjacent said illuminating means for converting said changes to electrical signals, means for transmitting said electrical signals to a remote station, and indicating means located at said remote station adapted to respond to said elec trical signals, whereby the light reflecting ability of said surface is continuously indicated at said remote station.

3. An earth strata differentiating device for a remotely controlled bore mining machine having a rotary cutting head with earth strata cutting means mounted thereon comprising, in combination, illuminating means mounted on said rotary cutting head in proximity to said earth strata cutting means for lighting a point which traverses the surface cut by said earth strata cutting means, means responsive to changes in the intensity of light reflected from said point mounted adjacent said illuminating means for converting said changes to electrical signals, means for transmitting said electrical signals to a remote station, and indicating means located at said remote station adapted to respond to said electrical signals, whereby the light reflecting ability of said surface is continuously indicated at said remote station.

4. An earth strata differentiating device for a remotely controlled bore mining machine having a rotary cutting head equipped with main cutting teeth comprising, in combination, an auxiliary earth strata cutting tooth mounted on said rotary cutting head and positioned to cut the perimeter of the hole generated by said main cutting teeth, illuminating means mounted on said rotary cutting head in proximity to said auxiliary earth strata cutting tooth for lighting a point which traverses the surface cut by said auxiliary earth strata cutting tooth, means responsive to changes in the intensity of light reflected from said point mounted adjacent said illuminating means for converting said changes to electrical signals, means for transmitting said electrical signals to a remote station, and indicating means located at said remote station adapted to respond to said electrical signals, whereby the light reflecting ability of said surface is continuously indicated at said remote station.

5. In a bore mining system, a remotely controlled bore mining machine having a rotary cutting head equipped with main cutting teeth and provided with a radial arm,

and the combination therewith of a forwardly extending housing carried on the outer reach of said arm, an auxiliary earth strata cutting tooth rigidly secured near the forward end of said housing and extending radially of said rotary head beyond said housing for cutting the perimeter of the hole generated by said main cutting teeth, a lamp mounted in said housing near said auxiliary earth strata cutting tooth and positioned to direct light on the surface cut by said auxiliary earth strata cutting tooth, a photoelectric cell mounted in said housing adjacent said lamp and positioned so that light reflected from said surface impinges thereon to produce electrical signals varying with the intensity of the light, means for transmitting said electrical signals to a remote station, and indicating means located at said remote station adapted to respond to said electrical signals, whereby the light reflecting ability of said surface is continuously indicated at said remote station.

6. In a bore mining system, the combination as defined in claim 5 in which the indicating means comprises an oscilloscope having a rotary trace the rotation of which is synchronized with the rotation of the rotary cutting head.

References Cited UNITED STATES PATENTS 3,019,338 1/1962 Monaghan et a1 299-1X 3,294,449 12/1966 Hartley et a1. 299-1 FOREIGN PATENTS 154,513 10/1963 Russia.

ERNEST R. PURSER, Primary Examiner. 

1. AN EARTH STRATA DIFFERENTIATING DEVICE FOR MINING AND TUNNELING MACHINES HAVING EARTH STRATA CUTTING MEANS MOUNTED THEREON COMPRISING, IN COMBINATION, ILLUMINATING MEANS MOUNTED IN PROXIMITY TO SAID EARTH STRATA CUTTING MEANS FOR LIGHTING A POINT ON THE SURFACE CUT BY SAID EARTH STRATA CUTTING MEANS, MEANS RESPONSIVE TO CHANGES IN THE INTENSITY OF LIGHT REFLECTED FROM SAID POINT MOUNTED ADJACENT SAID ILLUMINATING MEANS FOR CONVERTING SAID CHANGES TO ELECTRICAL SIGNALS, MEANS FOR CONVERTING SAID ELECTRICAL SIGNALS TO AN OPERATOR CONTROL STATION, AND INDICATING MEANS LOCATED AT SAID OPERATOR CONTROL STATION ADAPTED TO RESPOND TO SAID ELECTRICAL SIGNALS, WHEREBY THE LIGHT REFLECTING ABILITY OF SAID SURFACE IS CONTINUOUSLY INDICATED AT SAID OPERATOR CONTROL STATION. 